@misc{MO_2021_3_a0,
     title = {Nikolai {Nikolaevich} {Konstantinov} passed away},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {2},
     year = {2021},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2021_3_a0/}
}